Centrifuge rotors are typically used in laboratory centrifuges to hold samples during centrifugation. While centrifuge rotors may vary significantly in construction and in size, one common rotor structure is a swing bucket rotor having a solid rotor body defining an outer rim or wall of the rotor, and a plurality of wells or bays in a number such as two, four, or six for example, distributed radially within the rotor body and arranged symmetrically about an axis of rotation. The presence of the outer rim or wall provides structural rigidity to the rotor, especially in view of the high dynamic forces experienced during centrifugation. Buckets are placed in the wells, and are configured to hold sample tubes or similar laboratory-type containers, each containing a particular fluid material. During high-speed rotation, the buckets are permitted to swing within the wells, with the attained generally horizontal orientation of the buckets facilitating radially outward movement of the material held in the tubes.
One conventional type of swing bucket centrifuge rotor includes a generally metallic rotor configured to support an even number of swing buckets, such as four, six, or eight, for example, on diametrically opposite sides of the rotational axis of the rotor. In rotors of this type, and because of the very high rotational speeds during centrifugation, the rotor bodies must be able to withstand the dynamic stresses and forces generated by the rapid rotation of the swing buckets about the central rotational axis. These dynamic stresses and forces may lead to failure of the metallic rotor, such as fatigue failure. Additionally or alternatively, conventional metallic rotors of this type are subject to corrosion and stress fatigue. Finally, the generally solid construction of conventional rotors results in rotors that are relatively heavy and which may be expensive to manufacture. A need therefore exists for improved swing bucket rotors that overcome these and other drawbacks of conventional centrifuge rotors.